Pipette system for the volumetric extraction and linear deposition of a suspended material

Abstract

Pipette system for the volumetric extraction and linear deposition of a suspended material, in particular cells or particles. The pipette system consists of a capillary containing a piston inserted in such a way as to prevent the passage of liquids. Part of the rim forming the orifice of the capillary has a projection. The width of the projection determines the width of the smear regardless of the diameter of the capillary, even when the deposition of the suspension onto the slide or the like is contactless.

What is claimed is: 
     
       1. Pipette system for the volumetric extraction and linear deposition of a suspended material, in particular cells or particles, said pipette system consisting essentially of a capillary containing a piston inserted therein in such a way as to prevent the passage of liquids, characterized in that a projection is mounted on or is part of the rim forming the orifice of said capillary, said projection only extending partway around the circumference of said rim, said projection not extending past the rim in any manner into the region of said orifice, said projection having a groove extending along the entire length of said projection and reaching right to the tip of said projection, said groove in said projection not extending past the rim into the region of said orifice, the width of said projection determining the width of the deposition regardless of the diameter of said capillary, even when the deposition of the suspension onto a slide or the like does not involve contract with said slide, the inner diameter of said rim of said orifice being equal to the inner diameter of said orifice throughout the rest of the entire capillary region into which the suspended material is drawn, and the end surface of said piston is flat and perpendicular to the axis of movement of said piston. 
     
     
       2. Pipette system as claimed in claim 1 wherein said projection is mounted on said rim of said orifice of said capillary. 
     
     
       3. Pipette system as claimed in claim 1 wherein part of said rim of said orifice of said capillary is shaped into said projection. 
     
     
       4. Pipette system as claimed in claim 1 wherein a groove covering the length of said projection and reaching right to the tip of said projection is provided with wettability. 
     
     
       5. Pipette system as claimed in claim 4 wherein said projection is mounted on said rim of said orifice of said capillary. 
     
     
       6. Pipette system as claimed in claim 4 wherein part of said rim of said orifice of said capillary is shaped into said projection. 
     
     
       7. Pipette system as claimed in claim 1 or claim 4 wherein said projection contains a hydrophilic coating in order to improve the wettability of said projection. 
     
     
       8. Pipette system as claimed in claim 7 wherein said projection is mounted on said rim of said orifice of said capillary. 
     
     
       9. Pipette system as claimed in claim 7 wherein part of said rim of said orifice of said capillary is shaped into said projection. 
     
     
       10. Pipette system as claimed in claim 1 wherein said projection contains a groove which has a width smaller than the diameter of said suspended material.